Shell case ejector chute



Dec. 5, 1961 w. w. BROTHERS, JR., ETAL 3,011,408

SHELL CASE EJEC'I'OR CHUTE Filed Nov. 19, 1959 2 Sheets-Sheet 1 IN VEN TORS 20 BY JAMES S- ELLARD JR.

ATTORNEYS .WILLIAM W. BROTHERS,JR.

Dec. 5, 1961 w. w. BROTHERS, JR., ElAL 3, 08

SHELL CASE EJECTOR CHUTE 2 Sheets-Sheet 2 Filed Nov. 19, 1959 JNVENTORS IAM W.BROTHERS, flrh'zs S.ELLARD, JR. LU... W

ATTORNEY United States Patent ()fiice 3,01 1,408 Patented Dec. 5, 1961 Force Filed Nov. 19, 1959, Ser. No. 854,202 4 Claims. (Cl. 89-33) This invention relates to a shell case ejection chute for ejecting, from an aircraft, empty shell cases and unfired rounds of ammunition accumulated during the firing of high rate of fire automatic aircraft guns.

In the past it has been a common practice to store empty shell cases in the aircraft, removal being then accomplished after the aircraft had completed its mission and returned to the ground. This method of removal of spent ammunition cases is undesirable in modern supersonic jet aircraft where space and weight requirements are critical. Additional problems exist when the spent ammunition cases are merely permitted to drop freely from the aircraft since such factors as supersonic speeds, extreme altitudes and G loads are often present during the operation of high rate of fire automatic guns on high speed jet aircraft.

It has been found from experience that the aforementioned factors will cause a large percentage of freely falling shell cases to strike and damage the skin of the wings and fuselage of the aircraft over a wide area.

Efforts were made to develop a chute which would orient the shell cases base downward and eject them into the airstream in this position. It was found, however, that the case following the one entering the airstream interfered with the one entering the airstream, and caused the airstream to turn each case base upward, and nearly all of the cases then struck the aircraft. A means was then sought to boost the cases apart so that there would be no interference. Air jets Were used that proved very successful when large ai-r storage tanks were carried in the test aircraft, but some other means had to be found.

A pipe was constructed to conduct the gun blast gas aft to the shell case ejection chute, and the blast force from the gun could thus be utilized obviating the necessity of separate air storage tanks. This blast gas boosting system provided good shell case separation and the cases followed a uniform pattern away from the aircraft a long as the gun was fired. As soon as firing was stopped, however, these cases remaining above the jets in the chute fell out with no boost to steparate them. A means for preventing cases from dropping by gravity when the gun was not firing and not providing boost pressure was sought. A spring loaded gate was installed which held the cases in the chute above the jets. This caused a great deal of back pressure as the gun had to force each case past the gate. The piston of the present invention was then linked to the gate and arranged so that the blast pressure was bled off and ducted into the piston cylinder to force the gate open as long as there was blast pressure available. When the gun stopped firing, a spring forced the gate closed. Testing proved that this system was practical and effective.

An object of the present invention is to provide an ejection chute to dispose of spent shell casings accumulated during the firing of high rate of fire automatic aircraft guns wherein gas directed from the muzzle of the gun is used to increase the ejection velocity of the casing thus boosting it away from the aircraft.

A further object of the ejection chute of the present invention is to provide means for turning the empty shell case so that it leaves the aircraft in-a base downward altitude whereby the cases' balance and aerodynamic shape will cause it to fly away from the aircraft.

A still further object of the novel ejection chute of the present invention is to provide such a chute that will be operative during supersonic flight, at any flight altitude, and when extreme G loads are present.

According to the present invention the novel shell case ejection chute comprises a narrow twist inducing chute having guide rails therein, stop means disposed within said chute operable in response to gas from the muzzle of an automatic aircraft gun to release spent ammunition cases for ejection, and duct means in the sides of said ejection chute for boosting the discharge velocity'of said ammunition cases.

These, and other objects and features ofthe present invention will be obvious in light of detailed descriptions below and when taken in connection with the accom panying drawings, wherein: I

FIG. 1 is a partial exploded view of the ejection chute of the present invention; 7

FIG. 2 is a top view of the novel ejection chute;

FIG. 3 is a sectional view of the ejection chute of the present invention taken along the line 3-3 of FIG. 2; and

. FIG. 4 is a perspective view of the novel ejection chute of the present invention.

Referring now in detail to the drawings wherein like reference numerals designate like parts and more particularly to FIG. 1 there is shown the shell case ejection chute of the present invention generally designated 20. The chute 22 itself is substantially in the form of an inverted, twisted L having a front top panel 24 and a rear bottom panel 26. The side panels 28 and 30 are distinctly different and are formed in a manner to provide for the turning of the shell case to a base downward position. The first side panel 28 has a short radius turn therein while the second side panel 30 contains a long radius 90 turn thus imparting a 90 twist to the ejected shell cases and placing them in a base downward attitude as they leave the chute 22. p

The back panel 26 is provided with a rectangular opening 32 therein and a guide rail 33 on the inner side thereof. The guide rail 33 is positioned on the inner side of the back panel 26 a distance from the second side panel equal to the length of the shell casing 46 of the particular ammunition for which the ejection chute is designed.

The front panel 24 has a rectangular opening 34 identical in size and positioned directly opposite the opening 32 in the back panel 26. The holes 32 and 34 provide openings in the chute 22 through which gas from the gun muzzle (not shown) enters the chute to boost an empty shell casing or unfired round away from the aircraft. An additional rectangular opening 36 is positioned in the front panel 24 directly above the opening 34. A clearance dome 38 is also'provided in the front panel to permit the slug portion 40 of any unfired round 42 including the shell casing 46 to clear the front panel as the round is twisted to a bottom downward position. A pair of bar stiifeners 44 are welded one each to the front and back panels 24 and 26 to provide additional strength to the chute 22.

A short flanged pipe section 48 adapted to be attached to the gun blast tube adapter (not shown) just ahead of the gun barrel muzzle is connected to the chute 22 by means of a'pair of flexible tubes 50 and 52 and a pair of rectangular ducts 54 and 56. Each of the ducts 54 and 56 is provided with internal bafiling 58 to increase the gas pressure in the system. The ducts 54 and 56 enter the chute 2 2 through the rectangular holes 34 and 32 re spectively, and are permanently welded therein.

A piston chamber 66 is mounted above the flexible tube,

50 and the rectangular duct 54 by a pair of rigid supports 62. Said piston chamber 60 is connected to the gun. gas

blast conveying system by a short flexible tube 64 through 3 an opening 66 in the top portion of the rectangular duct 54. A piston head 68 is seated within the piston chamber 60 and has a piston rod 70 extending therefrom. A gate 72 is positioned within and attached to the chute 22 by a hinge 74 and is controlled by its integral gate arm 76 which enters the chute 22 through the rectangular opening 36. The gate arm 76 is attached near its mid-point to the piston rod 70 by a ball and socket type connection 78. A coil spring 80 is attached at one end to the outside of the bottom end of the piston chamber 60 by a hook 83. The other end of the coil spring 80 is attached to the gate arm 76 at the end thereof opposite the gate 72.

The upper end of the chute 22'is provided with an external flange 82 and a pair of U channels 84 to facilitate the adaption of the shell case ejection chute of the present invention to the cartridge ejection chamber of a standard high rate of fire automatic aircraft gun.

In operation the gate 72 will be in a closed position under the compressive action of the coil spring 80 prior to the firing of the automatic gun. In the initial position any shell cases ejected from the gun at the termination of the previous firing will be retained in the chute 22 by said gate. When the automatic gun is again actuated gas from the muzzle of the gun will be directed through the flexible tubes 50 and 52 and the ducts 54 and 56 to provide a jet-like downward blast through the baffles 58 into the chute 22. As the gas passes into the duct 54 a portion thereof is bled off through the flexible tube 64 into the piston chamber 60. Gas pressure on the face of the piston head 68 causes an up-stroke of the piston, which in turn causes the gate arm 76 to turn about the hinge 74 through the action of the piston rod 70 and the ball and socket connection 78 overcoming the compressive force of the coil spring 80. As the gate 72 opens empty shell cases and/ or unfired rounds are permitted to move therepast. After being released by the gate 72 the shell cases are guided to a base downward position by the twisted configuration of the chute 22 acting in conjunction with the guide rail 34. As the shell cases, in a base downward position pass the openings 32 and 34 in the chute they are struck by the jet-type gas blast exiting from the baffled opening of the ducts 54 and 56 thus boosting the spent shell cases away from the aircraft.

The reason for the retention of the shell case or cases after the gun has stopped firing is, as above noted, to prevent damage from cases accumulated in the tube when the gas blast from the gun is no longer available to exit the shells, and there is no blast force to keep them from dribbling along the skin of the aircraft. It is obvious that each spent shell casing is blasted from the chute by the blast of the cartridge preceding it so that when the gun stops firing, the last shell casing has no blast for removing it from the aircraft in a percussive and forceful manner. If it is not prevented, it will drop by gravity out of the chute and cause the damage noted above to the aircraft. The gate 72 is maintained in closed position when the gun is not being fired by means of the spring 80. When the gun is firing, there is suflicient blast force bled ofl through the tubes 64 to overcome the bias of the spring 80 and move the piston 60 to hold the gate 72 open. As soon as the firing stops, however, there is no blast to exert pressure on the piston 60 and the spring 80 again closes the gate 72 until such time as the firing begins again.

The present invention has been described in detail above for the purpose of illustration only and is not intended to be limited by this description or otherwise except as defined by the scope of the appended claims.

We claim:

1. In combination with an aircraft, a shell case ejection chute for ejecting empty shell cases and unfired rounds from said aircraft by means of gas blast from the muzzle of a gun mounted on said aircraft comprising a chute in the form of an inverted, twisted L, a guide rail on the inner surface of said chute to aid in turning ejected shell cases to a base downward position, a gate arm disposed within said chute, a pair of flexible tubes for conducting gas from the muzzle of an automatic aircraft gun to said chute, a pair of ducts connecting said pair of tubes to said chute, baffling within said ducts, a pair of oppositely disposed openings in said chute for receiving said ducts, a piston chamber mounted above one of said ducts, a flexible tube connecting said duct to said piston chamber, a piston located within said piston chamber having a piston rod extending therefrom, a ball and socket connection connecting said piston rod to said gate arm, spring means retaining said gate in a closed position within said chute when said gun is not being fired, said piston being operatively responsive to gas bled from said flexible tubes to keep said gate open to release unfired rounds and shell cases for ejection from said ejection chute as long as said gun is being fired, the blast gas from the gun muzzle operating to boost said shell cases away from said aircraft.

2. In combination an aircraft, automatic guns thereon having a high rate of fire, a shell case ejection chute of the type described comprising a narrow twist inducing chute, guide means operable in conjunction with said narrow chute to turn the shell cases to be ejected to a base downward position, stop means retaining said shell cases within said chute when said automatic weapons are not operating, a pair of gas conducting tubes connecting said chute to a gas producing source, means operable in response to gas passing through said tubes to remove said stop means from the path of said shell cases, and additional means to increase the velocity of the gas as it enters said chute whereby said shell cases will be boosted away from said aircraft.

3. In combination an aircraft, an automatic high rate of fire gun mounted thereon, a shell case ejection chute 0f the type described comprising a chute substantially rectangular in cross section, a gate having an arm extending therefrom disposed within said chute to prevent ejection of shell cases when said automatic weapon is not operating, spring means attached to said arm maintaining said gate in a closed position, a pair of flexible tubes for conducting gas from the muzzle of said automatic aircraft weapon to said chute, a pair of ducts connecting said pair of tubes to said chute, baffling within said ducts to increase the velocity of said gas as it enters said chute, a pair of oppositely disposed openings in said chute for receiving said ducts, a piston chamber mounted above one of said ducts, a flexible tube connecting said duct to said piston chamber, a piston head located within said piston chamber having a piston rod extending therefrom, a ball and socket connection connecting said piston rod to said gate arm intermediate said gate and said spring means, said piston being operatively responsive to gas from said aircraft gun muzzle to open said gate whereby said shell cases will pass said openings and be boosted away from said aircraft under the influence of said gas.

4. In combination with an aircraft having rapid fire automatic guns thereon, a shell case ejection chute of the type described comprising a narrow she1l-case-twisting chute, a duct leading into said chute from the muzzle of a gun to conduct gas therefrom to boost said shell cases away from said aircraft when said gun is fin'ng, stop means for retaining empty shell cases in said chute when said gun is not firing, means operable in response to gas bled from said duct to remove said stop means and allow ejection of said shell cases under the impact of the gun blast from the muzzle of said gun when the gun is fired.

Molins et al Jan. 29, 195.7 Shepard Aug. 5, 1958 

